Wouldn't most any girl have been attracted to this guy, or been flattered by his attention? Aruba or no Aruba? IOW's do you think he passed the smell test, if you can get past blaming Natalee for her poor judgment, as it turned out to be.
sw
You don't send a bunch of high-schoolers, particularly girls, off to a foreign island to live it up with little or no supervision. That is stupid, reckless, and in this case, probably deadly. Knowing a guy for a couple of days isn't the point.